Process of treating starch.



UNITED STATES PATENT osrron FREDERICK. SUPF, OF NEW YORK, N. Y., ASSIGNOR TO THE ARABOL MANUFAOlUR-IN G ()OM- PROCESS OF TREATING STARCH.

Specification of Letters Patent.

Patented April 20, 1909.

Application filed. June 2 7, 190%. Serial No. 440,68o.

To a-Zl'whmn it may concern:

Be itknown that I, FREDERICKSUPF, a subject of the Emperor of Germany, and a resident of New York, in the county of, New York and State of-New York, have invented certain new and useful Improvements. in Processes of Treating Starch, of which the following is a specification.

My invention relates to improvements in processes for treating starch; and it has for its object to render starch capable of swelling in cold water to a viscous mass, viz.to attain with cold water the same result as is ordinarily attained incooking up starch with hot water. 7 I am aware that various processes are known for producing a starch of this character, said rocesses dependin u on the destructive e 'ect ofcaustic. alka 'es upon the layers of the starch granules, normally unaffected by cold water. In order to prevent the swelling starch substance from forminga homogeneous tough mass with the water of the lye, the caustic 'alkalies have been dissolved in liquids suchas alcohol or concentrated salt solutions which permit the caustic alkalies to act, but prevent the swelling starch from uniting to a homogeneous mass. (See U. S. Patent N 0. 785,216 and German Patents Nos. 157,896; 166,259). Or, before allowing the caustic alkali to act thereon, the starch has been suspended in a water repellent medium, "for examplehydrocarbons, carbon tetrachlorid etc. (See U. S. Patents Nos.847,658 and847,985). All these processes, in order to produce a commercial product, require, that the swollen and exceedin ly voluminous mass be neutralized, which neutralization, however, results in a salt impregnated starch. If acid such as acetic, sulfuric, hydrochloric, nitric etc., which as a rule form hygroscopic salts, be employed for such neutralization, the' undesirablehygrosco ic property is also as-, sumed by the stem mass. :In order to avoid this difiicult and objectionable process of neutralization and to obtain a cold swelling starch free from all salts, I have sought in the present process a reagent acting on starch similarly to the caustic alkalies, neutral in itself and which could be readily and completely removed from the stare mass. In the salts of sulfocyanic acid, such as ammonium or potassium sulfocyanate, I

' have found these desirable properties. These diastase or of aci salts have also the further valuable proper ties of being practically completely recoverable by washing out with a suitable. solvent such as alcohol, acetone etc., which dissolves the same without allowing the starch to flow together to a homogeneous mass The result of this process is, that without causing starch to flow together to form a homogeneous mass, the layers of the starch normally unaffected by cold water, are so altered as to no longer protect the starch from swelling therein. Being less active in their chemical behavior toward starch than the caustic alkalies, the sulfocyanaltes are applicable dissolved sim ly in water and without any additions, provi ed the proper concentration, temperature and quantity of the solution are maintained. The

activity of-the suliocyanic acid salts may be In carrying out my process I take, for ex ample, 100 parts b weight of pulverized dry starch such as or 'nary potato starch, and treat this with 80 parts of a 50% solution of ammonium sulfoc anate' in water and to which have been acl ded 40 parts of alcohol, and thoroughly mix the starch and solution by stirrin A small amount of so dium sulfite may e employed to prevent discoloration due to slight quantities of. iron sometimes present as an impurity. The salt is then washed out with alcohol, acetone etc., which, as well as thesalt, is in a techmeal sense quantitativel recoverable, so

that all the reagents emp oyed in the proc-" ess may be re'e'mpleyed without appreciable loss. The resultlng product is in a technical sense, a pure starch which possesses the valuable property of swelling m'cold water to a homo eneous mass such as formerly was obtaine only through boiling. This product further possesses, at ordinary temperatures, so far as it has been possibleto examine the same, all the pro ertieawhichstarch as a rule possesses ony after beconufi'g. pasty through the action of higher'temperatures. It may for exanilple, through the action of theother reagents such as calcium and mag 1188111111 chi r d, borax, sulfonates, and 80111? be co veited at ordinary temperature. Also, the solutions of all of parts of pulverized, d1? potato starch with f -forth is not altered, so that thick cooking ble oils and fats act on the starch in the cold state in the same manner as upon the boiled starch. The specific character of the starch treated according to the process herein setter, consisting in treating the starch with a solution of ammonium sulfocyanate. '1

.3. The herein described rocess for rendering starch capable of swe ling in cold water, consisting in treating by weight100 80 parts of a 50% so tion of ammonium 1 sulfocyanate in water to which have been added 40 arts of alcohol. r

4. The erein described rocess for rendering starch capable of swe ing in cold '41-? ter, consisting in treating the starch with a suitable solution of a sulfocyanate, and then washing the same with a suitable solvent.

5. The herein'described process for rendering starch capable of swe ling in cold water, consisting in treating starch with a suitable solution of a sulfocyanate and to which alcohol has been added, and then washing the same with alcohol until the salt has been removed.

Signed at New York in the county of New York and State of New York this 25th day of June A.. l). 1908.

. FREDE ltlCli Sl'Pl.

Witnesses -FREDER1OK D. U'r'rnnr,

A. F. Voror. 

